KRT5 and Barrett esophagus: We observed significant downregulation in mRNA expression for squamous epithelium-specific genes such as KRT1, KRT4, KRT5, KRT6A-C, KRT13, KRT14, KRT15, KRT16, KRT23 and KRT24 in human BE biopsies as compared with samples collected from normal squamous esophageal epithelium.